Micrometer caliper



Patented Jan. 20, 1948 UNITED STATES ATENT OFFICE 4 Claims.

ment for reading thousandths of an inch of thicknesses as well as interior and exterior diameters of objects. ,In other words, this invention consists of a micrometer caliper particularly suitable for such purposes, namely, the reading of minute measurements.

An embodiment of this invention is illustrated in the accompanying drawings, wherein similar reference characters refer to the same parts in different views, and wherein:

Figure 1 represents a right side elevation of the instrument closed.

Figure 2 is a left side elevation and part section of th instrument closed.

Figure 3 is an end elevation and part section of the instrument, with the interior movable parts removed.

Figure 4 is a cross section on line 4-4 of Figure 1.

Figure 5 is an extension scale for use in taking larger measurements.

Figure 6 is a side elevation of the instrument of Figure 1 attached to a handle or adapter.

Figure 7 is a cross section of Figure 6 on line 1-1.

Figure 8 is an elevation of the adapter as seen from the reverse side to Figure 6, and

Figure 9 is a section along line 99 of Figure 6.

Referring first to Figures 1 to 4, illustrating the principal parts of the invention, reference numeral l represents an elongated frame open at one end in which a slid II is guided for longitudinal displacement. For this purpose their edges are beveled, as at l2, in Figure 4, and a thin portion l3 connects the right and left sides of the frame to provide sufiicient rigidity and keep the slide in position.

On the right side, Figure 1, is shown a pair of flat parallel faced jaws l4, l of which the upper one [4 forms part of the frame [0, while the lower one I5 is part of the slide II and between which laws the object D to be measured is calipered between said fiat faces on the jaws in the usual manner and. read off from one of the several scales I6, metric and inches with decimals or fractions thereof furnished along the edges of the slide l I, against the zero line I! on the frame ID, the characters of the scales being indicated at I la at the top of the slide l I.

To caliper small interior diameters of a tube, a pair of bits I la, [5a are provided at the outer ends of the jaws as usual.

The upper end of the frame I0 is provided with a yoke or crown l8 bridging the opening between 2 the two sides of the frame with its fiat middle portion 28 and extending downwardly with the U-sectional shanks l8a a short distance along the frames. The yoke is firmly but removably secured on the frame by a pair of screws l9.

At the upper end of the flat slide I l is a cylindrical head 20 containing part of the micrometer or precision measuring elements of this instrument. This head, shown in part section in Figure 2, is permanently secured, as at Ila, to the end of the slide or scale proper II. The head 20 has a central, threaded bore engaging the micrometer screw 2| preferably having a pitch of /40 of an inch in order to make 0.001 inch readings on the Vernier 22 divided into 25 equal spaces at the edge of thimble 23 as read off against an inch scale 24 divided into tenths and fortieths, see Fig. 6. This scale, 24 is not visible, when the instrument is set at zero.

The thimble or skirt 23 and the screw 2| constitute parts of the actuating, cylindrical body 25 mounted to turn on the axis of the frame Ill. It abuts with its fiat top face against the crown or yoke l8 through the intermediary of a thrust bearing 26. Both of these bearings are anti-friction' bearings of the usual ball or roller type. On the upper side of the yoke I 8 is placed another thrust bearing 21 and the cylindrical body has an axial pin 30 threaded to engage the knurled actuating button 29 which is held firmly in set position without axial play on the pin 30. It will thus be seen that parts 2|, 23, 25 will all turn together to cause the slide H with its head 20 to be axially displaced without turning so that the coarse readings of a calibration may be read 01f on one of the scales l6 against the zero mark at H.

It will also be understood that th micrometer readings will be made with the aid of the decimal scale 24 and the vernier 22 in the usual manner.

If at'any time diameters of more than three inches for which slide II is marked, is to be read an extension scale 32 is provided for temporary attachment at the lower end of slide 1 l, for which purpose holes 33 are indicated.

In Figures 6, 7 and 8 is shown an adapter or handle 35 for a more convenient use of the instrument, particularly for larger diameters of shafts, bars or axles. This adapter consists of an arcuate grip 36 preferably of I-shaped cross section with rounded outer surfaces, as at 31, to provide a comfortable hold and with transverse holes for lightness.

The upper end of the adapter 35 is provided with side ledges 38 spaced to fit the width of the frame H which is held firmly therein by a set screw 39 secured by a lock nut 40. The use of the instrument with the adapter 35 is the same as stated, with regard to Figures 1 to 4, and an example is indicated in Figure 6, wherein an object D is inserted between the jaws I4, l5.

It is understood that the invention as here disclosed is not limited to the details here described and shown, but that the same may be varied widely without departing from the spirit of the invention as defined by the subj'oined claims.

I claim:

1. A micrometer caliper comprising a frame member having a pair of parallel 182358. yokedetachably secured to the free ends of said legs and having a central aperture therein, said frame and legs defining a slot, one end of .sa-id slot being enlarged, bevelled edges on said parallel legs, a slide positioned in said slot and engaging said bevelled edges, jaws projecting from said slide and a side of said frame, set screws secured .to said yoke engaging said legs, means for 'regulating the distance between said jaws said means including a drum having 'a bevelled skirt, .a bevelled portion connecting said enlargement in said 25 1,477,533

slot and receiving said bevelled skirt, a head adjustably received in said drum having said slide secured thereto, means extending through said central aperture and secured to said drum for rotating said drum.

2. The combination of claim 1 and said lastmentioned means including a threaded stud having a knob detachably associated therewith.

3. The combination of claim 2 and thrust bearings on said stud engaging said' yoke.

4. The combination of cl'aim'3 and an arcuate handle detachably secured to said legs and selectively positioned longitudinally on said legs.

JOSE PERIZ AMADOR.

IREFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 517,208 Billings .Mar. :27, 1894 552,659 Brown Jan. 7, 1896 933,309 Keeter Sept. 7, 1909 

